1. Field of the Invention
The present invention relates to a structure for locking a cap-member to a cylindrical body.
2. Description of the Related Art
FIGS.5 and 6 show a prior art locking structure of a cap-member to a cylindrical body disclosed in Japanese Patent Application Laid-open No. 7-153529 (hereinafter "JP '529").
In this structure, a plurality of locking projections 53, facing each other, are provided on an inner surface of a peripheral wall 52 of a cap-member 51, and an annular engaging groove 55 relative to the locking projections 53 is provided on a cylindrical body 54.
With respect to the above structure of JP '529, however, the cap-member 51 having been locked to the cylindrical body 54 can not be easily detached since the locking projections 53 are not resilient.
Further, the locldng projection 53 is apt to be plastically deformed on fitting of the cap-member 51, which causes incomplete lock of the cap-member 51 to the cylindrical body 54.
Japanese, Patent Application Laid-open No. 8-279372 (hereinafter "JP '372") therefore discloses another locking structure of a cap-member to a cylindrical body as shown in FIGS. 7 and 8.
In this structure, a pair of resilient locking arms 64 with respective slits are provided oppositely to each other in a fitting direction (V-direction) of a cylindrical body 61 and a cap-member 62, and a free end portion of each of the locking arms 64 is provided with a locking projection 65. With respect to the structure of JP '372, however, it would be difficult to make the locking arm 64 have sufficient resilience because of a short arm-length D. D.